Appliance for airplane launching track



l I 1 March 31, 1931. E. HEINKEIL 1,793,331

APPLIANCE'FOR AIRPLANE LAUNCHING TRACK Filed April 19, 1930 INVENTOR lLENsT HEINKEL- A TTORNEY.

Patented Mar. 31, 1931 UNITED STATES ERNST HEINKEL, OF-WARNEMUNDE, GERMAN! APPLIANCE FOR AIRPLANi'J-LAUNCHING, TRACK Application filed April 19, 1930, Serial No.

My invention relates to the launching of flying machines on trackways on which they are rapidly propelled by power-operated means and are thus accelerated to the speed I necessary for rising into the air and more particularly to sleighs or cars on which the flying machine is carried during the starting action.

As a matter of fact, heretofore the structural elements attached to the body of airplanes and supporting the latter during the launching action were so designed and arranged that the centre of gravity S of the flying machine 1 was directly above the centre of the respective launching appliance 2, i. e. in the vertical plane of symmetry passing through the centre of the sleigh or-car, or in other words above the middle point between the front slides or shoes 5 andthe rear shoes 5', engaging the trackway 3 and positively holding the sleigh 2 on the latter.

In this case the weight of the flying machine was substantially uniformly distributed between both shoes 5 and 5, and it was thought that the latter would both be subjected to approximately equal stresses and the same Wear and tear resulting from the load and from' the friction caused during the launching action.

My experiments-however have shown that in practice the rear shoes 5 are subjected to a much higher load and considerably greater stresses than the front shoes, causing undue and excessive friction and premature wear of the rear shoes, and seriously impairing the work done by the propelling rope 4.

The principal object of this invention is to overcome said drawbacks and to provide an improved sleigh or. car of simple design which will smoothly slide along the traclway, causing no undue friction and no premature wear.

Other objects of the invention will inci- 5 dentally, appear hereinafter.

The nature and scope of the invention are briefly out-lined in the appended claims and will be more fully understood from the i01 lowing specification taken together with the accompanying drawing, diagrammatically 445,772, and in Germany April 18, 1929.

showing by way of example a flying boat and a sleigh supporting the latter.

I According to this invention, the bottom of the flying boat 1 and the upper platform of the sleigh 2 are designed so as to support the flying boat in a specific manner: i. e. with the centre of gravity S of the latter in a staggered position relatively to the vertical plane of symmetry passing transversely through the centre of the sleigh 2, or in other words the centre of gravity S of the flying boat is not directly above the centre of the sleigh but advanced forwardly in the starting direction, approximately above the front shoes 5, the forward end of the sleigh, thus carrying substantially the greater part of the weight of the flying machine while the latter is at rest.

On ropelling the sleigh a new virtual centre o gravity will arise by reason of the external forces acting upon the flying machine viz. its air resistance and its own inertia.

While the air resistance as may be safely assumed is in practice balanced substantially by the propelling action of the flying machines own propeller, the momentum caused by its inertia represents a considerable load K in the direction of arrow shown which eX- ceeds two-three or more times that of the flying machine proper. The force K produces on the front sliding shoe 5 a vertical upward force P and on the rear gliding shoe 5, a vertical downward force P. The upward force at 5, P is unfavourable both for the sliding shoe 5 and therefore by having the centre of gravity forward, the upward force P at 5 is reduced and the downward force P at 5 isalso reduced.

Various changes and modifications may be made in the design of sleighs or cars for the purpose described without substantially deviating from the spirit and the salient ideas of my invention.

What I claim is:

1. in flying machines adapted to be carried on a power propelled launching appliance, the arrangement of the supporting elements proper of the flying machine and of the the trackway 3 and i launching appliance in such manner that the centre of gravity of the flying machine is situated forwardly i. e. in the flying direction, of the centre of the launching appliance.

In flying machines adapted to be carried on a power propelled. launching appliance, the arrangement of the supporting elements proper of the flying machine and of the launching appliance in such manner that the centre of gravity of the flying machine is substantially directly above the front sliding shoes of the launching appliance.

In testimony whereof I aflix my signature.

ERNST 'HEINKEL. 

